Sheet metal knob



(No Model.)

J. SPRUCE.

SHEET METAL KNOB. No. 302,046. v PatentedJu'ly 15, 1884.

a State of Connecticut, have invented a new Imknobs which are made in parts struck up ing within the knob. This construction nepensive operation.

' UNITED STATES PATENT rion.

' JAMES SPRUCE, OF WATERBURY, OONNEOTI GUTJASSIGNOR TO THE SCO- VILL MANUFACTURING COMPANY, OF SAME 'PLAOE.

SHEET-METAL KNOB.

sPncIPIcA'noN forming part of Letters Patent No. 302,046, dated July is, 1884.

Application filed October 1, 1883. (No model.)

1'0 aZZ whom it may cancer-n.-

Be it known that I, J AMES SPRUoE, of Waterbury, in the county of New Haven and provement in Sheet-Metal Knobs; and I do hereby declare the following, when taken in" connection with accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure 1, a vertical central section of the knob complete; Fig. 2, a vertical central section of the body of the knob with the nut introduced; Fig. 3, asectional perspective view of the nut.

This invention relates to an improvement in from sheet metal, the several parts secured together to form an ornamental knob, and such as used on stoves and for like purposes. These knobs are attached by means of a nut fixed in or made a part of the knob that is to say, the knob is fitted with a female thread corresponding to a male thread attached to or made a part of thestove-door, or to whatever the knob is to be attached, or may be a screw introduced through ahole in the door and into the threaded hole in the knob. A common method of making this class of knobs. is to construct a nut of polygonal shape, or having its edge irregular or roughened, and that introduced into the cup-shapedbase part of the knob, and then the metal spun down onto the knob, the irregularities in the surface of the nut causing the metal of the knob to so en gage the nut as to prevent the nut from turn-' cessitates the placing of the knob in the lathe for the purpose of spinning, which is an ex- The object of my invention is to so apply the nut that it may be done by astamping operation; and the invention consists in constructing the nut with its under face concave, and of a diameter corresponding to the interior of the base end of the knob prepared to receive it, and when placed in the lower part of the knob the nut is struck to bring its iin- 'der face into a horizontal plane, thereby extending the face and edges of. the nut and correspondingly expanding the surrounding portion of the shell of the knob, whereby a firm attachment is made between the shell of the knob and the nut, so as to prevent thedisengagement of the one from the other, as more fully hereinafter described.

A represents the body or shell of the knob, which is struck from sheet metal, preferably its lower or base end, B, closed, except as to a central hole, a. struck in the usual manner for drawing up cup-shaped articles of sheet metal.

,0 is the nut. It is made cylindrical, and concave upon itsunder side, preferably convex on its oppositeside, as shown, but may be flat upon that side, as indicated in broken lines, Fig. 2. The diameter of the nut corresponds to the internal diameter of the base end of the body of the knob and which it closely fits when set therein, as seen in Fig. 2. The nut having been placed within the body This part of the knob is of the knob, as seen in Fig.- 2, it is struck to nut is thus struck down the interior of the body of the knob at the top of the nut is, like the nut,

less in diameter than at the extreme bottom.

This expansion of the extremelower end of the knob without corresponding expansion above and corresponding expansion of the nut causes the two to interlock, so that no axial movement of the nut is permitted, and the expani sion of the nut forcing a corresponding expansion of the body of the knob produces so great a friction between the adjacent surfaces of the body of the knob and nut that the nut cannot be turned within the knob under any ordinary usage;

The nut may be punched and threaded before it is placed within the knob, or the nut sozoie may be drilled and tapped nller it, is in the knob.

The knob is completed by adding the cap 1) or other parts in the usual manner of ma];-

5 ing sheet-metal knobs.

I claim The herein-described llllPlOVOlllGlll] in the manufacture of sheet-metal knobs, consisting in striking up the body A from sheet metal,

10 to produce substantially a cup-shaped base or lower end, then introducing a eoneave-snr- I faced nut into the base concave side downward, the periphery of the nut corresponding in shape and size'substantially to the interior of said enp-shaped base then striking the nut to bring its previously-concaved surface into a flat plane within said base, substantially as described.

.TAS. SPRUCE. \Vitnesses:

M. L. SPERRY, G. M. DE Mo'r'r. 

